This invention pertains to modems, particularly to modems for use in CDMA (Code Division Multiple Access) radio systems, and most particularly to modems able to function in any of several different generations or standards of CDMA radio systems.
CDMA radio systems are well known. See, generally, CDMA Cellular Mobile Communications and Network Security, Dr. Man Young Rhee, Prentice Hall 1998, ISBN 0-13-598418-1.
Currently,xe2x80x9csecond generationxe2x80x9d CDMA systems, often referred to in the art as xe2x80x9c2Gxe2x80x9d systems, governed by standard TIA/EIA/IS-95, hereinafterxe2x80x9cIS-95xe2x80x9d, are widely used. The third generation of CDMA systems, such as cdma2000 and UMTS UTRA systems are being introduced as a extensions of IS-95 systems.
Each of those three systems has to date required the use of different terminals or base stations for different air interface standards. This results in great inconvenience to consumers and burdens the service providers with extra operating costs.
There is thus a need to provide CDMA equipment that can function under each of the IS-95, UMTS UTRA, and cdma2000 standards.
It is thus an object of the present invention to provide an efficient soft modem architecture that can accommodate third generation (cdma2000, UMTS UTRA) and one second generation (IS-95) standards.
It is a further object of the present invention to provide a CDMA modem that is configurable over a broad range of uses.
It is a further object of the present invention to provide a CDMA modem definable by software.
In accordance with the teachings of the present invention, these and other objects may be accomplished by the present systems and methods in a modem configurable to operate in a variety of environments each representing a different air interface standard. An embodiment of the present invention includes a method of CDMA communication comprising configuring the components of a modem which are common to the cdma2000, UMTS UTRA, and IS-95 air interface standards as hard-wired components, and configuring the components unique to each of those air interface standards as software-configurable components. Another embodiment of the present invention comprises a modem with hard-wired circuitry to perform functions common to those three air interface standards and software-configurable elements to perform functions unique to any of those three air interface standards.